About 20 Catholics sat on folding chairs and old sofas in Ed Burg's basement, snacking on cookies and candy and talking about why they don't like the proposed marriage amendment.

"It's a matter of further restriction on gay or GLBT people of whom there are number in my family, particularly my son," said Burg, 88, who attends St. Edward's Catholic Church in Bloomington.

Last week's meeting was one of several recently organized by Catholics who oppose the proposed constitutional amendment to ban same-sex marriage, putting them at odds with Catholic bishops and underscoring the deep divide and tension among Catholics over the issue of gay marriage. On Wednesday, several hundred Catholics met in Minneapolis' Loring Park to sing, dance, pray and show support for same-sex marriage.

So far this year, Catholic leadership has been one of the biggest financial backers of pro-amendment forces, directing close to $500,000 in support of it. Minnesota voters will decide Nov. 6 whether the state's Constitution will define marriage as a union between a man and a woman.

While conservative Catholics have thrown their support behind the amendment, the more liberal-minded like Burg have rallied against the measure and believe bishops should instead be more focused on fighting issues like poverty and homelessness.

"I certainly see [it] as damaging ... in the impression that we give of ourselves as a state, if we pass this," Burg said just prior to the meeting at his house, where a representative with an anti-amendment group urged them to encourage others to vote against the measure.

Jeff Wheeler, Star Tribune

Michael Dodson of Minneapolis sang Wednesday with other attendees at a Loring Park rally by Catholics for Marriage Equality.

Uncommon voting bloc

Catholic voters have played pivotal roles in the outcome of gay marriage measures in other states and are expected to do the same in Minnesota, where they rank as the state's largest religious denomination with nearly 1.1 million followers.

But unlike evangelicals and other conservative religious groups who have played key roles in supporting anti-gay marriage measures in other states, Catholics appear less likely to vote as a bloc on issues like gay marriage.

Recent national polls report increased support for gay marriage in the United States. According to a survey released by Pew Forum on Religion and Public Life in July, 58 percent of Catholics are in favor of allowing gays and lesbians to marry.

"Catholics are actually more likely than most other religious groups to be in favor of allowing gays and lesbians to marry," said Besheer Mohamed, a Pew research associate. "White evangelical Protestants ... three-quarters of them oppose allowing gays and lesbians to marry."

A deep divide

The Minnesota chapter of Catholics for Marriage Equality, which organized Wednesday's Loring Park event, formed after bishops mailed copies of an anti-gay marriage DVD to nearly 400,000 Minnesota Catholics in 2010. The Minnesota Catholic Conference -- the public policy voice of the Catholic Church in the state -- previously has said the group "does not speak for the Catholic Church."

Jim Smith, a board member with Catholics for Marriage Equality, said a number of Catholics in Minnesota don't approve of the bishops' campaign.

"There are faithful Catholics who may not be currently on board with gay marriage or marriage equality but are deeply uncomfortable with the church spending so much money and time to enshrine this amendment into our constitution," he said. "There are many faithful Catholics who deeply believe gay couples and gay parents pose absolutely no threats to heterosexual families."

While evangelicals and other conservative religious groups also have come out in support of the amendment, Catholic bishops have been among the most vocal supporters, chief among them Twin Cities Archbishop John Nienstedt, who directed to clergy there should be no "open dissension" of the church's support of the amendment.

Statewide outreach

Church parishes were directed to form committees to work for passage of the amendment. The archdiocese also appointed priests and married couples to visit archdiocesan high schools this spring to talk about marriage.

Catholic Conference leadership has been going to churches across the state -- giving talks supporting the idea that marriage should only be between a man and woman -- and will continue to do so through the fall.

The conference has about 450 church captains statewide "coordinating educational, prayer, and outreach efforts with thousands of active volunteers," said Jason Adkins, executive director of the conference.

"We've found that majority of Catholics who attend church and practice their faith strongly support the marriage amendment," he said in a statement. "We recognize that some Catholics are against the amendment for, sometimes, very personal reasons. But we are concerned about efforts to mislead them concerning what the church teaches, and the effect of the amendment."

Covert meetings

Renee Jones Schneider, Star Tribune

A group of Catholics from St. Edward's Church in Bloomington met at the home of Ed Berg to discuss their support of the marriage amendment and what they could to defeat the amendment. They're meeting in Berg's home because they don't feel like they can have an open and honest discussion at St. Edward's.

Groups of lay Catholics and former priests have spoken out against the bishops' campaign. Some parents and students also have criticized the church's move to talk about marriage in high schools. Active Catholics have met in Protestant churches to talk about how to defeat the amendment.

Catholics and other faith groups have held meetings in their homes, like the one at Burg's house, where representatives for the anti-amendment Minnesotans United for All Families encourage them to hold conversations with friends and family.

Kate Brickman, a spokeswoman for the group, said anti-amendment Catholics feel like they have to meet in their homes and other non-Catholic spaces because bishops aren't tolerant of their views.

While Catholic leadership has supported similar marriage amendments in other states, it's been particularly "ardent" in Minnesota, according to Laura Olson, a political science professor at Clemson University, who's written about marriage amendments.

Olson said bishops may believe the amendment has a good chance of failing and are putting a lot of energy into trying to get it passed, although such actions could have the opposite effect with some, who'd rather see church money used for "social justice issues."

"Among Catholics, and this would be true in Minnesota and nationwide, you've got about a third who are pretty ... traditional in their interpretation and adhere to what the bishops say. What the remaining two-thirds do is really the issue."